[IR] update testdata: print whole string concatenation at one line

compiler/testData/ir/irText/classes/lambdaInDataClassDefaultParameter.kt.txt

@@ -21,10 +21,7 @@ data class A {
   }
 
   override fun toString(): String {
-    return "A(" + 
-"runA=" + 
-<this>.#runA + 
-")"
+    return "A(" + "runA=" + <this>.#runA + ")"
   }
 
   override fun hashCode(): Int {
@@ -78,10 +75,7 @@ data class B {
   }
 
   override fun toString(): String {
-    return "B(" + 
-"x=" + 
-<this>.#x + 
-")"
+    return "B(" + "x=" + <this>.#x + ")"
   }
 
   override fun hashCode(): Int {